1. Field of the Invention
The present invention relates to associating an ophthalmic lens with data carrier, more particularly it relates to providing the characteristics of lenses, such as prescriptive contact lenses or intra-ocular lenses.
2. Description of the Prior Art
The contact lens market in the United States is a multi-billion dollar market. Recent data indicate that nearly 36 million Americans—almost 13% of all Americans—wear contact lenses. There are numerous manufacturers of contact lenses and many different channels of distribution, including eye care practitioners (e.g., ophthalmologists and optometrists), national and regional optical chains, mass merchants, and mail order and Internet firms. The contact lenses include any of the following basic types: soft, rigid gas permeable and hard. Soft contact lenses are made of a highly flexible material that contains water or silicone or hydrophilic hydrogels, oxygen can reach the eye when soft contacts are used. Rigid gas permeable contact lenses, frequently referred to as RGP contact lenses, are composed of a firm plastic material and do not contain water. RGP lenses permit oxygen to pass directly through the lens to the eye so that it may “breathe.” Because they transmit oxygen, these lenses are referred to as gas permeable. Hard contact lenses are made of a hard plastic material. Hard lenses, also called PMMA lenses, were the first mass-market contact lenses. Unlike RGP lenses, PMMA lenses do not allow oxygen to pass through the lens to the eye.
Contact lenses are often manufactured with identifying marks useful for indicating which contact lens goes into which eye, or indicating serial numbers, lot and batch numbers, and optical powers.
The methods for providing identifying marks are well known in the machine tooling and contact lens field, for example, using a laser, electrical discharge, machining, mechanical scribing, diamond scribing, ultrasonic scribing, holographic marking, and scattering by surface disruption. These markings such as brand name, on the edge may help to identify between the right and left contact lenses.
One such solution is presented by JP1990000114677 which discloses a system for the identification of right and left contact lenses and to prevent the danger of inducing a hazard in the cornea by coloring either of the right and left contact lenses.
Another solution is presented by U.S. Pat. No. 6,203,156 which discloses identifying marks for each contact lens corresponding to each eye.
The disadvantage of the proposals in the prior art is that they are manufacturing intensive; and depend on the user being able to visually distinguish the often small markings on the contact lenses in order to determine the correct contact lens for each eye. This practice can introduce errors in the determination and is time consuming.
It is thus one of the objects of this invention to mitigate or obviate at least one of the aforementioned disadvantages.